[1] Multiple filter holders, in Melles Griot Product Catalog 1999, p. 24.11.
[2] 12800 Multiple filter holder, in The Book of Photon Tools, Oriel Instruments 1999, p. 18-7.
[3] Filter and optic holders, in Optics and Mechanics 1999/2000 Catalog, Newport p. 13-57 and 13-59.
[4] multiple filter mounts, in Optics and Optical Instruments Catalog 2002, Edmund Scientific p. 127.
This invention is aimed at improvement of mechanical holders, which are used for securing and maintaining optical elements such as filters, plates, mirrors, or other similar objects, precisely in a particular position with respect to alignment, and replacement of such elements without loss of that alignment.
In the fields of optics and lasers it is necessary to hold the optical elements precisely aligned along the path of a light beam. Typically, optical holders must hold a plurality of optical elements having different shapes and diameters at a needed position and, at the same time, they have to allow optical elements to be quickly interchanged. For the sake of brevity, only filters are discussed throughout the rest of this specification, it being understood that the same considerations discussed herein are also applicable to other optical elements such as wave plates, mirrors, beam splitters, and so forth.
Optical filter holders known presently are capable of holding filters having a relatively small range of diameters or rectangular shape dimensions. Hence, several separate holders of various sizes must be used for any practical work with optical and laser systems.
For example, the filter holders presented in the product catalog of Melles Griot Corporation, published in 1999, page 24.11, are specifically for 1xe2x80x3 or 2xe2x80x3 filters only. Filters of other sizes can not be positioned in those holders in a stable manner since they will be hold in position by touching the semi-circular grooves of the filter holder in two points only. This is demonstrated in FIG. 1. The holder 10 has a semicircular shape with a trench 30 at the bottom part to accommodate the tips of rectangular holders. The dashed line 20 in FIG. 1 indicates the depth of the grooves. The diameter of the circular filter 40 is smaller than the diameter of the filter holder 10 and therefore the filter is equilibrated only due to touching the base of the holder in two points. The diameter of the circular filter 60 is larger than the diameter of the holder 10, and therefore it is equilibrated by touching the two edges of the filter holder. If the rectangular filter 50 does not have sizes precisely related to the parameters of the holder, its equilibrium will also be supported in two points only. Since, the groove width shall be larger than the thickness of the filters, only filters of precisely predetermined shape are stable in such a holder.
Similarly, Newport Corporation in its Catalog for 1999/2000, page 13-57, offers two filter holders, one for a single or a stack of 2xe2x80x3 square filters, and the second one for holding a single or two round 2xe2x80x3 diameter filters.
Adjustable lens holders similar to those shown in Melles Griot Catalog (p. 23-4 and 23-6) can be used for holding both spherical and cylindrical lenses of different sizes. These lens holders require a vertical cross bar assembly, incorporating a central thumbscrew, to hold the lens in its position. Changing a lens in such a holder would require using both hands of the user: one for loosening the thumbscrew, and one for holding the lens. Whereas this is acceptable for lenses, it is not convenient for filers, which are replaced very frequently in most optical setups. The vertical posts that keep together the bottom grooved plate and the vertical cross bar restrict the access to the filter in a single holder and eliminate access to the filters in case such holders are combined in a row for holding multiple filters. Adaptation of such a lens holder for holding multiple filters would require multiple mounting posts increasing the sizes, the weight and the cost of such an element.
A multiple lens holder that allows easy access to each individual lens is disclosed in the U.S. Pat. No. 5,446,596 to Mostrorocco. However, the capability of holding multiple lenses with easy access to each individual lens is achieved in the device disclosed in the U.S. Pat. No. 5,446,596 by positioning the lenses side by side in pairs. Such a positioning is adequate for the procedure of tinting ophthalmic lenses discussed in the U.S. Pat. No. 5,446,596 to Mostrorocco, however, it is not useful for the purposes of controlling laser beams and for other physical optics applications and systems where it is necessary to hold the optical elements aligned subsequently along the propagation path of the light beam.
In view of disadvantages of the prior art outlined above, it is the primary objective of this invention to provide an optical holder which allows to mount, align, and replace both rectangular and round optical filters, wave plates, substrates and other similar elements of different sizes quickly, without loss of alignment and with improved stability of positioning.
Another objective of the invention is to provide a filter holder with variable angle between the grooved side plates for centering the axes and improving the stability of filters of different sizes.